View Full Version : stocking a 40 gallon peacock tank

10-25-2006, 09:54 PM
i will be stocking a 40 high tank with peacock cichlids very soon and was wondering how many you guys would/have put in this size tank. it will probably have an emperor 400 and a fluval 304 on there and will get weekly 50-75% water changes.

10-26-2006, 05:19 AM
I don't hace an answer for you but could you explain the theory behind 75% water changes. I read in another post here somewhere about it but would like more info. Like....you said someone convinced you to do it...how? And...do you age the water and adjust a few days prior to introduction to the tank or go straight from the tap? I may try this on my 30 gal so the more info the better. Sorry to pirate your thread but I had to ask. :)

10-27-2006, 11:06 PM
feel free to always ask about stuff like that. i used to buy into the mindset that big water changes will screw things up, like your biological or the pH, stuff like that. but in fact they help if anything. water changes wont affect your biological colonies. the good bacteria live ON surfaces in the water, not IN the water column itself. the only thing they use it for is to spread (as in: from the gravel bed, to the tank wall, to the biological filter, to the surface of the plants, etc). so you could (and i have) do 100% water changes and have absolutely no ill effect to your biological filtration. and as for pH, thats only a concern if your tap isnt good for your fish. over time different things build up in the water that will change the pH. for example nitrates form nitric acid and therefore lower your pH over time. so big frequent water changes help keep the pH closer to your tap water's, so when the water changes are done there is little or no difference in tank and tap pH, whereas if you do smaller and/or less frequent water changes the pH in the tank may shift and therefore it will be a bigger change in pH when you do the water change. but that just explains why its not bad. its good for many reasons. mainly that the big frequent water changes help dilute problematic chemicals. nitrates are a biggy. you may hear not to let them go over 40ppm or something, but that just means at MOST, but really the lower the better. as an analogy sometimes there are limits to certain chemicals in the air for humans. so if it is bad to go outside if chemical x is over 20 ppm, it still isnt good for you if they are just below that, the lower the better. so the lower you can keep the nitrates, the better for the fish. nitrates lowly stress fish over time and can lead to decreased growth, health, and general ability to thrive. so the lower you can keep them the better. there are other dissolved organic compounds that also affect fish in the same way, but i cant remember the names or details for them off hand. the other one that i know of is that many fish expel growth inhibiting hormones that inhibit the growth of the same or sometimes similar species. in nature this is good because it gives the big individuals more time to breed and produce more young before other individuals are big enough to compete with them for that right. so big frequent water changes keeps these growth inhibiting hormones to a minimum. in nature when the dry season hits, the volumes of water drop, concentrating these chemicals even more, reducing growth, and the bigger the fish the more waste, so in nature no one needs to be growing in the dry season and therefore producing even more waste in these ever decreasing bodies of water. so it makes it ever so slightly more likely that more fish make it through the dry season. so the bigger and more frequent water changes, the less like the dry season. so i tried this new water change schedule and what i thought was thriving before, was pretty good, but it was not thriving. i saw greatly improved growth rate, max size, coloration, fewer health problems at all, and a general increased ability to thrive. the other thing is that regardless of the reasons, in order to breed, the fish have to be thriving. and many if not most breeders rely on water changes to help keep their fish in the absolute best condition possible. i am on well water so my tap can go straight into the tanks. my tap is also 7.0, which is good for everyone except the african cichlids who get the proper dose of lake salt and buffer added at the beginning of the water being added so it mixes as the water is added. it is easy to bring pH up, but it is very hard to bring it down. so if you need it down from your tap, you need to have it ready before the water change. that is why i carry out and highly recommend big frequent water changes at or about the rate of 50-75% weekly.

10-27-2006, 11:54 PM
Wow - great info. Well water can go straight into a tank with no treatment? I'm on well water and I still treat - guess I could have saved some time, money and supplies. Do you still put in stresscoat? I think I might try your theory out.... Thanks for sharing.

10-28-2006, 12:15 AM
its not just theory, its science and that means it works. ive recommended it to many customers (i work in a pet shop) and any that actually do it comment on how much better their fish do. every source for well water is different so some are great for certain fish and others you cant keep much in at all. i dont even use stress coat, doesnt really do anything that helps. what else do you do? i add beffuer and salt to my african cichlid tank, and there are certain additives for other types of tanks, but in general you shouldnt really need anything besides a dechlorinator if you are on city water.

10-28-2006, 01:41 AM
I add the water conditioner and stresscoat. That's it. How do I find out if my water is safe without that? I will take your advice - starting tomorrow with my weekly water change - and I'll let you know how it goes. Thanks.

10-28-2006, 02:04 AM
what do you mean water conditioner? (brand, exact product name) because that usually means dechlorinator, which stress coat is, so as is you may be wasting money by doubling up on products. test your tap for pH, nitrates, ammonia, etc. for well water, if your LFS has kits for it have them test for heavy metals or you might be able to get that from the water company, or i guess water service company. because that would be something that is variable with well water, heavy metals. and if you have them you would have to use a water conditioner that detoxifies heavy metals. you definitely have them if you get those copper or iron stains by drains and faucets in your house.

Lady Hobbs
10-28-2006, 03:24 AM
Well water does not need a declorinator but still contains metals in the water. Stress Coat should still be used.

10-28-2006, 01:04 PM
every source of well water is different, so they dont all have toxic levels of heavy metals. if unsure it is safer to assume they do, but in general you should be able to find out whether you even need to add a heavy metal detoxifier.

and on an added note to my big post, another thing that frequent big water changes do is keep the level of trace elements higher. low trace element levels are believed to cause or at least contribute to hole in the head and head and lateral line erosion.

Lady Hobbs
10-28-2006, 01:11 PM
I have done very large water changes myself with absolutely no ill effects on any of my fish. I've done 75% several times. I see it as no different than adding new fish to a brand new tank. That doesn't kill them and neither do large water changes.

Your posts are very informative and well written. Thanks

10-28-2006, 01:17 PM
it is very stressful for fish to be put into a new tank (whether they are the first inhabitants or they are being added to an established setup). big water changes may be kind of stressful at first depending on the fish, but the fish will very quickly learn the routine and even eat during the water change. i would work my way up to 75% if they're not used to it. if they are used to 25% weekly, do a 50% one week and then a 75%, dont just jump from 25% once a month to 75% a week.